INTRODUCTION: The standard induction chemotherapy in newly diagnosed acute myeloid leukemia (AML) is 7 days cytarabine and 3 days daunorubicin. However older and frail patients cannot be treated intensively. Before hypomethylating agents (HMA) plus venetoclax (VEN) was established we formulated a more tolerable induction therapy for these patients using continuous infusions of reduced doses of cytarabine (A) and idarubicin (IDA) in combination with ATRA (A), the (A)-AIDA regimen and trying to reach noteworthy and relevant remission rates with acceptable toxicities in this special population.

METHODS: Between 1998 and 2015 older/frail patients with newly diagnosed or relapsed AML received (A)-AIDA. Treatment consisted of cytarabine 100mg/m2/d d1-5 and idarubicin 5mg/m2/d d1-5 as continuous infusion. Since 2003 ATRA (45 mg/m²/d d4-6, 15 mg/m²/d d7-28) was added in some patients.

RESULTS: 154 patients received (A)-AIDA, median age was 71 years. In 40% the AML was secondary, 15.6% had relapsed AML. The complete remission rate was 41%, 7% reached a partial remission, the median overall survival was7 months. No significant differences of remission rates regarding various known risk factors for outcome with (A)-AIDA were detected.

CONLUSION: Recent studies established HMA/venetoclax as first-line treatment for older/frail AML patients. Because (A)-AIDA is equally effective in patients with secondary or relapsed AML or ECOG>1, this regimen is an interesting treatment option for patients uneligible to HMA/venetoclax regimens.